1. Field of the Invention
The invention relates to a balancing shaft for an internal combustion engine and to a method for the production thereof.
2. Related Art of the Invention
A balancing shaft of the generic type or a method of the generic type for the production thereof has been disclosed by DE 198 32 987 A1. The balancing shaft described there is of tubular design and has in its interior a balancing weight which extends virtually over its entire length. The tubular part in this case is provided at the circumference with two recesses which each have a centrally situated hole. Passing through each hole is a pin, which in like manner projects through the balancing shaft. The pin serves in this case to fasten the balancing weight to the tubular part. The tubular part is closed at both ends by a cap by pressing the latter into position or by brazing. In the case of the balancing shaft described, the fastening is very laborious, since either the pin has to be locked from the interior of the balancing shaft or, if the pin is already arranged in the balancing shaft, the balancing weight has to be laboriously pushed back and forth until the pin is threaded through the hole in the wall of the tubular part and can then be locked from outside. Furthermore, the practical requirements imposed on a balancing shaft are rarely such as can be gathered from the known publication. This is because the local arrangement of the balancing weight is usually desired. In order to be able to fulfill its function, the balancing weight in this case must have a certain size. However, the larger said balancing weight has to be, the greater the volume required by the balancing weight. In order to achieve this in the known balancing shaft, the diameter of the tubular part must increase in accordance with the increase in the space taken up locally by the balancing weight. The result of this is that such a balancing shaft takes up an enormous construction space such as is not available as a rule nowadays in modern engines.